Synergistic effects on hydrogenated TiO2 for photodegradation of synthetic compounds pollutants

• Disordered TiO2 wider adsorption profile in visible light and improved photocatalytic efficiency by hydrogenation.
• Formation of O2 vacancies by reduction electron–hole recombination rate and improved charge transport.
• Higher photo activity of hydrogenated TiO2 by high surface to bulk defect ratio.

Hydrogenation is an easy and low cost method for modification on light adsorption of TiO2 which has received immense attention owing to its highly ordered morphology and structure, perpendicular electron transfer channels and excellent electric conductivity. Also, hydrogenation is a simple and facile process in that it does not involve the use of a catalyst, other chemicals and does not need further treatment including separation and purification. Thus, hydrogenation treatment of TiO2 has been regarded as an effective way to obtain an efficient photo catalyst by improving its specific capacitance, surface disorder, O2 vacancies, donor density and stability by controlling the introduction of O2 vacancy states. Furthermore, the OH group introduced on TiO2 modifies the electrochemical activity of TiO2 thus increase its pseudo capacitance. In order to increase the efficiency the hydrogenated process normally complies with doped of metal and metal ions. It's expected that the solar absorption coefficient and wavelength range of hydrogenated TiO2 increased as doping process, increase the separation and the electrons transportation of electrons and holes. Thus, designing the hydrogenation and doping process considered as simple and versatile methods to overcome the limits solar adsorption, fast electron hole pair recombination and poor electrochemical activity and conductivity of TiO2. This provides new option into the photocatalytic of hydrogenated TiO2 and pave the way for further studies of other hydrogenated and doped metal oxides for photocatalytic applications.